Well, not really. But researchers at University of California, San Diego School of Medicine
have induced this all-too-common human experience – or a close version
of it – permanently in rats and from what is observed, hope they can perhaps derive
clues about why strokes and Alzheimer's disease can destroy a person’s
sense of direction, according to newswise.com.

Scientists have developed a micro-surgical procedure that makes it
possible to remove the area of the rat’s brain that contains grid cells
and show what happens to this hard-wired navigational system when these
grid cells are wiped out. One effect, not surprisingly, is that
the rats become very poor at tasks requiring internal map-making skills,
such as remembering the location of a resting platform in a water maze
test.

“Their loss of spatial memory formation was not a surprise,” the Web site quotes
senior co-author Robert Clark, PhD, a professor of psychiatry. “It’s
what would be expected, based on the physiological characteristics of
that area of the brain,” which is the first brain region to break down in Alzheimer’s disease.

But
the rats retained a host of other memory and navigation-related skills
that scientists had previously speculated would be destroyed without
grid cells.

“The surprise is the discovery of the type of memory
formation that was not disrupted by the removal of the grid cell area,”
Clark said.

UC San Diego scientists were able to show that even without grid
cells rats could still mark spatial changes in their environment. They
could, for example, notice when an object in a familiar environment was
moved a few inches and they could recognize objects, such as a coffee
mug or flower vase, and remember later that they had seen these objects
before.

(This is a habit that drives my husband and son crazy. I know the placement of every object in the kitchen and when even a spoon is moved, I know it.)

Electrical recordings of signals transmitted from the brain suggested that the animals had developed place cells – cells
that are believed to convey a sense of location – and that these cells
were firing when an animal passed through a familiar place.

“Their place cells were less precise and less stable, but they were
present and active,” said Clark, who is also a research scientist at
Veterans Affairs San Diego Healthcare System. “That was a surprise
because we had removed the spatially modulated grid-cell input to these
neurons.”

"Our work shows a crisp division of labor within memory circuits of the
brain,” he said. “Removing the grid-cell network removes memory for
places but leaves completely intact a whole host of other important
memory abilities like recognition memory and memory of fearful events.”

Comments

Post a Comment

Popular posts from this blog

For all of you out there who got straight A's and scored high on your SAT (if you can remember back that far!), it doesn't necessarily mean that you can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face- matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people’s visual ability and that these variations are not associated with individuals’ general intelligence, or IQ.

“People may think they can tell how good they are at identifying objects visually,” says Isabel Gauthier, David K. Wilson Professor of Psychology at Vanderbilt University, who headed the study. “But it turns out that they are not very good at evaluating their own skills relative to others.”
In the past, research in visual object recognition has fo…

Researchers from Leeds Beckett University are challenging the myth that extreme sports enthusiasts push themselves to the max and take risks no matter what the consequences.

Wingsuit flying is a relatively new parachute sport which involves a specifically designed jumpsuit that facilitates forward motion and directional control, according to newswise.com. It is considered the most dangerous parachute sport as it involves flying close to structures at speeds of over 200 mph, where a mistake or accident would most likely result in death, the web site maintains.

“When you think of the people involved in such extreme sports, you tend to think of risk takers who push themselves to the limit," says Dr Eric Brymer, a Reader in the Carnegie School of Sport. &quo…

How can something invented barely 20 years ago in Japan (has it really been that long?). And who came up with the word???

In any event, a new report investigates what effect they have on pretty much the last place you'd expect them. The workplace. Or, at least, the places I worked. In fact, sending and receiving emojis in the workplace could have an impact on productivity and innovation in the workplace, according to newswise.com.

University of Delaware management professor Kyle Emich has explored the effects of emotions on teams and performance and is now taking on what effect, if any, they have on innovation and productivity.
"In our lab, we normally induce emotional states by showing people happy or sad video clips or pictures," he tells newswise.com. "For example, we…

I'm in the frenetic, not fast, lane, writing a medical technology web column about robots and imaging and all the ways you can stave off aging (if only) and essays about parenting without losing your sanity, and trying to raise a 10-year-old!